The present invention relates to improved roofing components. More particularly, this invention relates to transition assemblies for protecting and reducing the stresses at roof deck perimeters and parapet walls.
Conventional roof deck design typically calls for wood blocking at the termination points of the roof deck assembly and at the transitions between multiple roof decks, such as expansion joints. The wood blocking is used to provide starting and stopping points for the roof decking, roof insulation, and the roof covering, as well as an anchorage medium for sheet metal flashing and gutter hardware. The wood members can be made a part of the assembly, or can act as fillers, independent from the roof deck assembly, being mounted to a wall or other non-roof deck component. Roof deck stress occurs at the joints between the wood blocking and roof assembly and at the termination points of the roof deck.
As relatively thin, plate-like structures, roofs experience diaphragm forces due to building movement induced by wind and seismic loading. These diaphragm forces result in stress between roof components, especially at roof transition and termination points. These stresses are transferred to the wood blocking and roof supporting structure. Further stress is caused by linear expansion and contraction forces. Since the roof components are formed of different materials with different coefficients of thermal expansion, they can undergo significant relative thermal growth. Such relative movement results in local stresses between the roofing and blocking materials and between the roof assembly and the roof support system. These stresses also occur at the junctures between multiple roof assemblies.
Further problems arise with wood blocking as the wood ages. As it dries, the wood shrinks, warps and buckles, losing its dimensional stability and its ability to retain fasteners. This presents problems for building flashing as it causes substrate movement and fastener loosening resulting in leaks and failures.
To deal with these problems, there is need for improved protection from the stresses between the roof deck and the roof supporting structure at the roof deck perimeter and between adjoining roof assemblies.
A roof transition assembly suitable for roof perimeter and wall transitions. The roof transition assembly is for use with roof decks with a sheet of rigid material and a sheet of corrugated material. The roof transition perimeter assembly comprises a base component and an upper component The base component has two legs: one secured to the sheet of corrugated material, the second extending upward along the roof deck edge. The base component further has a connecting surface for attachment to the upper component. The upper component has a connector portion and an anchor portion, with the anchor portion secured to the top of the roof deck. The connector portion extends from the anchor portion, overlays, and is secured to, the connecting surface of the base component, thus anchoring the transition assembly to the roof deck.
The transition assembly for a roof deck and a parapet wall has a base component and a wall component. The base component, as in the perimeter assembly, has two legs. The first leg is attached to the corrugated sheet of the roof deck, and the second leg extends generally parallel to and overlaps a portion of the parapet wall. The second leg again has a connecting portion for securement to the wall component. The wall component has a connector portion, and a hook portion. The hook portion extends over the top of the parapet wall, and the connector portion overlays and is secured to the connecting surface of the base component, thus anchoring the transition assembly to the roof deck and parapet wall.
The parapet wall transition assembly can further be fitted with a cant component. The cant component is positioned at the intersection of the parapet wall and the roof deck. The cant component has a central portion and a leg extending from each end of the central portion. One leg is secured to the roof deck and the second leg extends up the parapet wall and is secured to the wall component.